Draft gear



' March 19, 1929. w, H, T 1,705,635

DRAFT GEAR Filed NOV. 15, 1923 5 Sheets-Sheet 1 I'Wolter K W Match 19, 1929. I w. H. COTTON DRAFT 'GEAR Filed Nov. 15, 1923 3 Sheets-Sheet 2 March 19, 1929. w. H. COTTON 1,705,635

DRAFT GEAR S Sheets-Sheet Filed Nov. 15, 1925 [raven r: WGLZZGI 1 6 0660);

v A v Patented Mar. 19, 1929.

-WALTEB H.0OTTO'N, OF CHICAGO, IIiLINOIS, .ASSIGNOR TO UNION .DR'AZET GEAR COM- PANY, OF GHICAGO,'ILLI1\TOIS, A 'COR-BORATI-ON OF DELAWARE.

DRAFT GEAR.

Application filed. November 15, 19231 Serial No. 674,972.

The invention relates to draft gears for railway cars, beingparticularly adapted for.

use in freight service.

' The principal object of the invention is to secure a high efficiency by providing for the development of the. maximum resistance ofthe gear at the inception of compressive action, and the maintenance of suchmaximum resistancenntil the, gear is completely closed. i

The gear isfurthermore so organized that certainty of release is secured. Further. ad. vantages ofthegearwill appear in connection with its descriptionaand manner of oporation. v

A preferred embodiment ofthe improved ings, in which Fig. 1 is a central plan section ofthe gear as applied to-a car;

Fig. 2 is a sectional view of the gear on the line 22 0fFig.. 1; Fig.3 is a plan section in part-similar'to Fig. 1 but mainly immediately above the friction elements, thegear being shown in full compression Figs. 4. and 5 are viewsin perspective of the wedging elements;

Fig. 6 isan elevation. of one Oh series of friction plates of uniformshape;

Fig. 7 is a viewsimilar to Fig. 1, showing, the wedging and friction elements mainly in plan; I a

8 -is acentral vertical section ofthe gear showing a modified :form ofconstrue tionyand Fig. 9 is a perspective view of one of the parts of the draft gear.

For the purpose of showing. the manner of 'mounting the gear in-acar there is represented-aipair of draft or center sills at =10, 10,

a pair ofdraft lugs'at=1'1,a1l,a pair of bufling lugs at- 12, 12,-the butt 01 3; coupler M13, and a commonfonn of yoke'or coupler extension at.

14. These 'elements1forn1 no. part of: the invention, and 1 may be of any preferred form. The gear is shown as comprising a plate followerz15, andra chamberedfollower 1,6, the T formerheingz associated with the draft lugs zandthelat-ter with :the buffing lugs, though their relative positions may be reversed with- I outchangingtheaction of the device. lVithin the chambered 1 follower 16,:and associated,

- respectively, wvitli its two side walls, are two i of releasing elements.

ear is illustrated in theaccompanying draw- .endwise displacement. .21, comprise seats for a series of releasmg groups of friction plates 17 18, each group being composed of two sets of intercalating plates of uniform shape, one of which is shown at 19 (Fig. 6). r

The friction plates are shown as bifurcated or U-shaped, thus providing a transverse horizontal chamber for the accommodation The actual tying. to-

gether ofthe upper and lower longitudinal members of the frictionp'lates by means of an integral transverse portion, as shown,

while desirable, is not essential,it be inglimportant that friction plates be provided above and below the releasing elements (any suitablev means for preventing vertical dis placement of the upper-plates.being used),

member of the .U-shaped plateforms a shoulderfor this purpose.

The two sets of friction plates of each i group are normally so disposed that their united or shoulderedends, for convenience such that their opposite or'forward ends are spaced a suflicient distance .fromathe other .and that the plates have shouldersfor ,envgagement by a releasing element. The crossfollowerto permit themaximum compressive travel.

Within the chamber between the upper and lower legs ofthe friction plates, andengagingthe retracting shoulders of .each, are a pair of bars 20, QLeXtendin g from sidewall to side wall of the chambered fol-lower, 16. Thebar 20, which-is-adjacent theouter or i open end of this follower, is of such horizontal width that it at no time emerges entirely beyond the casing, thereby preventing its Thetwo 'bars 20,

springs, as. 22, shown as five in number. I VVedgmg elements, hav ng their contacting faces sharplyacute to the axis oftheggear,

areinterposed between the two groups 17, 18, of the friction plates. ments, as 23, is bifurcated inform to'provide a continuance ofthe chamber within which the releasing elements are housed. The.

closed end of this wedging element is normally seated against the plate follower 15., and bears forwardly upon the-adjacent relea-sing bar 20. Each leg of the e'lement23, is provided with a plurality of wedgingfaces,

One of these ele- V bered follower.

v as 24, 25, thebase 26 of the inner wedge 25 behorizontal webs 31, 32, the webs of the two elements being relatively so disposed that they constitute, respectively, the upper and lower wall of a spring chamber.

Housed within the chambersthus formed, and reacting between the seats 26, 30, are a pair of friction developing springs 33, 34-. In assembling the gear the springs 33, 34, are introduced under compression, and their reaction forces the cooperating wedging faces into engagement and consequently maintains a corresponding degree of lateral pressure upon the two groups of friction plates.

The wedging elements 27 are at all times out of contact with the cross member of the chambered follower. The inner plate of each group, in contact with the wedges, is of the set which cooperates directly with the cham- The long taper of the wedging faces produces a very powerful wedging action, of which there is an immediate maximum development at the commencement of the compression of the gear.

Under the influence of buffing stresses, with the gear and its parts normally positioned as shown in Figs. 1 and 7, the follower-15 moves.

backwardly, carrying with it the wedging element 23 and the releasing bar 20. The advance of the wedging elements 27 being resisted by their frictional engagement with the adjacent friction plate, a maximum development of wedging action upon the friction plates immediately occurs.- The follower 15 now comes into engagement with the set of friction plates located adjacent to it and forces them forwardly between the members of the other set of plates, their advance being resisted by the high friction due to the action of the wedges, the resistance continuing uniform throughout the entire compressive movement, which is arrested when the follower 15 comes into engagement with the ends of the walls of the follower 16, as shown in Fig. 3.

The inward movement of the follower 15 and with it of the bar 20, has caused a compression of the releasing springs 22. When thebufling stresses are removed the releasing springs force backwardly the bar 20, and with it the wedging element 23. As the elements 27 lag by reason of their frictional engagement with astatlonary plate, the compressive action on the two groups of plates is relievednormal position.

The bar 20 presently engaging the shoulders of the two sets of friction plates which had been advanced, carries these plates back to The wedging elements 27 follow up the element 23under the influence of the springs 33, 34. The release, while prompt and certain, isjwithout violence because some degree of wedging pressure is constantly exerted upon the two groups of friction'plates. I

Under the mfluence of draft stresses like results are secured, the wedge elements '27 being carried forward bythe frictional engagement therewith of the ad]ace nt plate which, as stated, is assoclated with and acted d1rectly upon by the follower 16.

While a highly efficient and, so far as now advised, a preferred form of. construction is shown and described, various changes of detail may be made within the scope of the invention. For example, in place of the springs 33, 34, for holding the wedging elements nor-.

mally in wedging engagement, a spring may be employed which will react against one of the followers, as in the modification of Figs. 8 and 9. In this modification there is substituted for the pair of wedging elements 27 a single bifurcated element 35, the cross-member 36 of which constitutes a seat for a spring 37, which reacts against the bar 21, the central releasing spring of the set 22 being omitted.

The action of the gear in its modified form is the same as in the form previously 'described, with the exception that the spring 37 acts upon the wedging element 35 to oppose or cause its longitudinal movement as the gear is compressed as means for augmenting the wedging action. This spring is, however, preferablyquitelight, and the, action last referred to is negligible.

I- claim as my invention 1. A wedging member for use in a draft gear, comprising a body member provided with a plurality of inclined wedging portions a shoulderbetween said wedging'portions, said shoulder adapted to form an abutment for a spring, and a web connecting said wedging portions. s

2. In a draft gear, a plurality of wedging members provided with a plurality of inclined wedging portions, the wedging portions of one member engaging the wedging portions of the other member, certain of said portions being opposed and provided with abutments, resilient means between saidabutments tending to cause said members to move along said inclined surfaces, and flanges on said'members for enclosing said resilient means.

3. In a draft gear, in combination, a chambered follower, a follower 0p osed thereto, two groups of intercalating riction plates enclosed within the chambered follower, each group comprising two sets of plates, the plates of each set of each group being end wise engageable by one of the followers, cooperating wedging elements interposed between the two groups of plates, and in frictional contact therewith, resilient means between said elements, one of such elements being acted upon positively by one of the followers, the longitudinal positioning of the other wedging element being depend ent mainly on its frictional engagement with one of the friction plates, and means for returning the parts to normal position after compression.

4:. In a draft gear, in combination, a chambered follower, a follower opposed thereto, two groups of intercalating friction plates enclosed within the chambered follower, each group comprising two sets of plates, the plates of each set of each group being endwise engageable by one of the followers, co-

operating wedging elements interposed be tween the two groups of plates and in frictional engagement therewith, one of such elements being acted upon positively by one of the followers, the longitudinal positioning of the other wedging element being dependent mainly on its frictional engagement with one of the friction plates, and spring means for normally urging the wedging elements together, and means for returning the parts to normal position after complexion.

5. In a draft gear, in combination, a pair of opposed followers, two groups of intercalating friction plates interposed between the followers, each group comprising two sets of plates, the plates of the two sets of each group being endwise engageable, respectively, with each follower, means to limit the lateral movement of said plates, cooperating wedging elements interposed between the two groups of plates, means for holding the wedges in wedging relation to the plates, one of said elements being positively controlled by one of the followers and the other of such elements being controlled by the other follower mainly by frictional engagement with a plate engageable bysuch follower, and means for returning the parts to normal position after compression.

6. In a draft gear, in combination, a chambered follower, an opposed follower, two groups of intercalating friction plates interposed between the followers, each group comprising two sets of plates, one set of plates being adapted to be engaged by one of said followers, the two sets of plates of each group being relatively longitudinally movable by the relative approach of the followers, a pair of cooperating wedging elements interposed between the two groups of plates,

and spring means positioned between said groups of plates and reacting between the two wedging elements for urging them together, and means for returning the parts to normal position after compression.

7. In a draft gear, apair of cooperating elementseach having a plurality of longitudinally arranged wedging portions in engagement with one another, the rear end of the advance wedging portion of each being formed as a shoulder, and an expansion spring reacting between such two' shoulders.

8. In a draft gear, in combination, a pair of coupler engaging followers, two groups of longitudinally disposed intercalated friction plates interposed between the followers, means for limiting outward lateral move ment of the plates, means interposed between the two groups of plates for exerting outwairlpressure thereon and arranged to de-v velop maximum pressure at. the initial comfaces, one of said elements being in contact with one of the named followers during the 7 initial compressive action. of the gear, and elements having sliding engagement with such faces, said elements comprising intercalated friction plates, said wedges being ar ranged to maintain a substantially uniformv pressure upon the second named element throughout their movement after the initial compressive movement of the gear.

10. In a draft gear, in combination, apair of opposed coupler engaging followers, one

thereof being a casing, two groups of intercalating friction plates'enclosed within the casing, a pair of cooperating wedging elements mterposed between and compressively acting upon the groups of plates,'one of such elements being floating and the'other being positively engageable by one of the named followers, spring means reacting between the wedging elements for urging them into engagement, each set of each group of plates being positively engageable by oneof the said followers, the inner plate of eachgroup being of the set which'is not engageable by the follower engageable'by the wedging element and other spring means for efiecting the release of the gear.

WALTER n. COTTON. 

